The embodiments of the subject matter described herein relate generally to vehicle diagnostic systems. More particularly, embodiments of the subject matter relate to a methodology for localizing ground offsets associated with an electronic device.
Various types of systems including, but not limited to automobiles, utilize numerous electronic control units (ECUs) configured to control various vehicle subsystems, such as the engine, transmission, airbags, antilock braking, cruise control, electric power steering, audio systems, windows, communications, doors and mirror adjustments. While some of these subsystems are independent, others require an exchange of data among one another during operation of the vehicle. When an ECU either fails or is operational but faulty, the vehicle may exhibit degraded performance or be completely disabled.
An ECU on the vehicle may experience a ground offset condition. A ground offset condition occurs when an expected reference voltage (e.g., zero volts) of an ECU has shifted. If such a condition occurs, then if this shifted signal voltage is measured relative to different reference voltages, then different measured values will be obtained.
In an ideal network of ECUs, each of the reference voltages are identical such that all signal voltage measurements are consistent relative to one another. Ground offsets in the ECUs can result in inconsistent vehicle operation, due to changing electrical loading. Moreover, ground offsets tend to degrade over time rendering the faulty ECU inoperable.